update deps
prune, shrinkwrap, list, fixes

Fixes:
- `cli-prompt` replaces deprecated `prompt` method of `commander`
- Use absolute junctions for XP, pending joyent/node#8813

New commands:
- `rnpm prune [--production]`
- `rnpm shrinkwrap`
- `rnpm list --depth=n`

New aliases and shorthands:
- `i`: install
- `ls`: list
- `--prod`: --production